Maxis is going to launch this soon, its a portable 3G/WiFi Hotspot device.
The device is a 3G modem that allows people to create portable WiFi hotspot, something like your WiFi modem. But this one uses the 3G network.
It is made by Huawei and could last about 3-4 hours(probably more, I have not personally tried it). Its being tested internally by Maxis.
P1 also has a similar device over here, probably might take years to launch.